Bill & Mike--- the mic looks much like a pencil -eraser end with 2 solder blobs on one end, black felt on the other.. That's the end you talk into..
The encoder is less than a postage stamp square, with a knob that rotates on top.. solder? pins on the bottom..
The BITX40 uses a 10K pot for tuning...not an encoder.
Larry W8LM
ARRL Life member - Licensed 368 DOG years..